There are two types of biaxial hinge that is a crossover-type biaxial hinge in which the first and second hinge shafts intersect each other, and parallel biaxial hinge in which the both hinge shafts are arranged in parallel. The invention relates to the latter, a parallel biaxial hinge.
The parallel biaxial hinge has advantage in comparison to uniaxial hinge that the first casing and the second casing connected via the hinge can be opened equally on the right and on the left, as if a book in the hands were opened. Such parallel biaxial hinge is known e.g. as is described in the Patent Document 1 below.
However, the biaxial hinge according to the Patent Document 1 has a problem in that, when a first casing is opened 90 degrees relative to a second casing, a rear side surface of the first casing comes to a position to cover a rear side surface of the second casing, which may interfere with various ports such as LAN ports, USB ports, etc., as well as power connector—i.e. those components often arranged on the rear side surface of the first casing—, then the cables connected with these components are also affected. Such an interference results in hindrance to their use, unsatisfactory heat exhaust and thus a reduced product life.
Still further, the biaxial hinge according to the Patent Document 1 has a problem in that it cannot effectively satisfy the recent needs for more lightweight and thinner notebook PC.
[Patent Document 1] JP Laid-Open Patent Application No. 2012-237392